Bivith, it's not just flaws in the DVD or a bad projector setup. The problem is so glaringly obvious when you see it on the screen that it cant be mistaken for anything else than an incompatibility issue or a hardware/software problem.

I work nearly everyday with SD material shown either on 32" LCD TVs or on our massive SANYO 2k videoprojector. In those cases you definitely see picture defects (for those in the know, try mixing a film with crappy heavily compressed video files from an AVID editor projected onto a cinema screen...).